We also have an upscale local grocery chain in town with baggers that will take your stuff out to your car if you want, but I hate it because it simply takes too long. Never go there unless I only need a few items, or something that only they carry. Their olive oil is sublime!
Even with lines, usually faster in the human-run checkout.
If you want faster lines, find one with only men in it. Men usually aren't the main grocery shopper in the family, so they're usually buying less, and usually aren't dealing with rambunctious kids, so they can focus on unloading and loading groceries. No purses either, so the credit card is usually in the machine right away.
I've pointed this out to my wife a few times and she simultaneously curses her fellow women and grudgingly accepts that I'm right and uses the logic. She's quite efficient, but I have to admit that if I saw her in line I probably wouldn't get behind her if she was smiling. (If she was wearing her resting bitch face, probably fine - typical sign of professional women who aren't inclined to spend any more time than necessary in the grocery. You find a woman in a pantsuit, she's probably faster than most men.)
My reward is not having to stand in a long line. I avoid cashiers like the plague, except in the case where a register just happens to open up near me and I'm the first or second one on line.
Not to mention that self-checkout lets me decide what goes in what bag without having to put it on the conveyor belt in a specific order.
Self checkout is just all-around far better than cashiers.